Christine C. Quinn, once the front-runner in the New York mayoral race, lost in the Democratic primary. A behind-the-scenes film captures the campaign’s final month.

From the start of the New York City mayoral race, Christine Quinn had it all: name recognition, an overflowing war chest and a seven-year record of accomplishment as City Council speaker. She was Mayor Michael Bloomberg’s heir apparent, on track to become the city’s first female and first openly gay mayor. Then, a month before the primary on Sept. 10, she began to slide in the polls.

This is the story of her collapse, as witnessed from within her campaign.